Universal Journal of Materials Science Vol. 5(4), pp. 102 - 110
DOI: 10.13189/ujms.2017.050404
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Mechanism and Morphology of Formation of Micropores in the Structure of DC Cast AlMgSi Alloy


I. Buljeta 1, Z. Zovko Brodarac 2, A. Beroš 1,*, M. Zeko 1
1 Faculty of Metallurgy and Materials Science, University of Zenica, Zenica, Bosnia and Herzegovina
2 Faculty of Metallurgy, University of Zagreb, Sisak, Croatia

ABSTRACT

The phenomena defects in the triple junction grain boundaries affect the properties of the microstructure of aluminum alloys. For that purpose the microstructure of the alloy EN AW 6060 on the billet sample cast by DC (Direct Chill) technology was analysed in order to gain insight into the origin and form pores in the final stages of solidification. Mechanisms of solidification shrinkage, thermal contraction and low permeability of interdendritic channels networks were discussed in moment when melt becomes isolated in separate locations forming new structure. Under such conditions, the tensile stress caused by anisotropic thermal contraction of a coherent dendrites network, causing the formation of pores in the corners of the grain boundaries whose morphology is determined by SEM / EDS analysis.

KEYWORDS
Micro Cavity-pores-voids, the Triple Point of Grain Boundaries, Hot Tearing, AlMgSi Alloy, Direct Chill Casting

Cite this paper
I. Buljeta , Z. Zovko Brodarac , A. Beroš , M. Zeko (2017). Mechanism and Morphology of Formation of Micropores in the Structure of DC Cast AlMgSi Alloy. Universal Journal of Materials Science, 5 , 102 - 110. doi: 10.13189/ujms.2017.050404.